Add documentation for proxy

Author: yciabaud

README.md

@@ -72,6 +72,27 @@ var optionalOpts = {
       left: 0,
       customParam: 'blah' // custom parameters supported
     }
+  },
+  // NodeJS HTTP agent implementation (used to proxy HTTP and Websocket requests in node)
+  httpAgent: {},
+  // Socks proxy options (used to proxy UDP requests in node)
+  socksProxyOpts: {
+      // Configuration from socks module (https://github.com/JoshGlazebrook/socks)
+      proxy: {
+          // IP Address of Proxy (Required)
+          ipaddress: "1.2.3.4",
+          // TCP Port of Proxy (Required)
+          port: 1080,
+          // Proxy Type 5 (Required)
+          // Type 4 does not support UDP association relay 
+          type: 5,
+  
+          // Authentication used for SOCKS 5 (when it's required) (Optional)
+          authentication: {
+              username: "Josh",
+              password: "somepassword"
+          }
+      }
   }
 }
 

lib/client/udp-tracker.js

@@ -68,8 +68,11 @@ UDPTracker.prototype._request = function (opts) {
     parsedUrl.port = 80
   }
   var timeout
+  // Socket used to connect to the socks server to create a relay, null if socks is disabled
   var proxySocket
+  // Socket used to connect to the tracker or to the socks relay if socks is enabled
   var socket
+  // Contains the host/port of the socks relay
   var relay
   var transactionId = genTransactionId()
   if (self.client._socksProxyOpts) {
@@ -218,10 +221,10 @@ UDPTracker.prototype._request = function (opts) {
     self.client.emit('warning', err)
   }
 
-  function send (message, info) {
-    if (info) {
+  function send (message, proxyInfo) {
+    if (proxyInfo) {
       var pack = Socks.createUDPFrame({ host: parsedUrl.hostname, port: parsedUrl.port }, message)
-      socket.send(pack, 0, pack.length, info.port, info.host)
+      socket.send(pack, 0, pack.length, proxyInfo.port, proxyInfo.host)
     } else {
       socket.send(message, 0, message.length, parsedUrl.port, parsedUrl.hostname)
     }